@nraynaud/xo-vhdmount
Version:
Node JS utility to expose the content of a VHD file as a raw disk file with FUSE
915 lines (699 loc) • 29.9 kB
JavaScript
'use strict';
var _promise = require('babel-runtime/core-js/promise');
var _promise2 = _interopRequireDefault(_promise);
var _regenerator = require('babel-runtime/regenerator');
var _regenerator2 = _interopRequireDefault(_regenerator);
var _asyncToGenerator2 = require('babel-runtime/helpers/asyncToGenerator');
var _asyncToGenerator3 = _interopRequireDefault(_asyncToGenerator2);
var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');
var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);
var _createClass2 = require('babel-runtime/helpers/createClass');
var _createClass3 = _interopRequireDefault(_createClass2);
var _typeof2 = require('babel-runtime/helpers/typeof');
var _typeof3 = _interopRequireDefault(_typeof2);
var _structFu = require('@nraynaud/struct-fu');
var _structFu2 = _interopRequireDefault(_structFu);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var VHD_UTIL_DEBUG = 0;
var debug = VHD_UTIL_DEBUG ? function (str) {
return console.log('[vhd-util]' + str);
} : function () {};
// ===================================================================
//
// Spec:
// https://www.microsoft.com/en-us/download/details.aspx?id=23850
//
// C implementation:
// https://github.com/rubiojr/vhd-util-convert
//
// ===================================================================
// Sizes in bytes.
var VHD_FOOTER_SIZE = 512;
var VHD_HEADER_SIZE = 1024;
var VHD_SECTOR_SIZE = 512;
// Block allocation table entry size. (Block addr)
var VHD_ENTRY_SIZE = 4;
var VHD_PARENT_LOCATOR_ENTRIES = 8;
var VHD_PLATFORM_CODE_NONE = 0;
// Types of backup treated. Others are not supported.
var HARD_DISK_TYPE_DYNAMIC = 3; // Full backup.
var HARD_DISK_TYPE_DIFFERENCING = 4; // Delta backup.
// Other.
var BLOCK_UNUSED = 0xFFFFFFFF;
var BIT_MASK = 0x80;
// ===================================================================
var fuFooter = _structFu2.default.struct([_structFu2.default.char('cookie', 8), // 0
_structFu2.default.uint32('features'), // 8
_structFu2.default.uint32('fileFormatVersion'), // 12
_structFu2.default.struct('dataOffset', [_structFu2.default.uint32('high'), // 16
_structFu2.default.uint32('low') // 20
]), _structFu2.default.uint32('timestamp'), // 24
_structFu2.default.char('creatorApplication', 4), // 28
_structFu2.default.uint32('creatorVersion'), // 32
_structFu2.default.uint32('creatorHostOs'), // 36
_structFu2.default.struct('originalSize', [// At the creation, current size of the hard disk.
_structFu2.default.uint32('high'), // 40
_structFu2.default.uint32('low') // 44
]), _structFu2.default.struct('currentSize', [// Current size of the virtual disk. At the creation: currentSize = originalSize.
_structFu2.default.uint32('high'), // 48
_structFu2.default.uint32('low') // 52
]), _structFu2.default.struct('diskGeometry', [_structFu2.default.uint16('cylinders'), // 56
_structFu2.default.uint8('heads'), // 58
_structFu2.default.uint8('sectorsPerTrackCylinder') // 59
]), _structFu2.default.uint32('diskType'), // 60 Disk type, must be equal to HARD_DISK_TYPE_DYNAMIC/HARD_DISK_TYPE_DIFFERENCING.
_structFu2.default.uint32('checksum'), // 64
_structFu2.default.uint8('uuid', 16), // 68
_structFu2.default.char('saved'), // 84
_structFu2.default.char('hidden'), // 85
_structFu2.default.char('reserved', 426) // 86
]);
var fuHeader = _structFu2.default.struct([_structFu2.default.char('cookie', 8), _structFu2.default.struct('dataOffset', [_structFu2.default.uint32('high'), _structFu2.default.uint32('low')]), _structFu2.default.struct('tableOffset', [// Absolute byte offset of the Block Allocation Table.
_structFu2.default.uint32('high'), _structFu2.default.uint32('low')]), _structFu2.default.uint32('headerVersion'), _structFu2.default.uint32('maxTableEntries'), // Max entries in the Block Allocation Table.
_structFu2.default.uint32('blockSize'), // Block size in bytes. Default (2097152 => 2MB)
_structFu2.default.uint32('checksum'), _structFu2.default.uint8('parentUuid', 16), _structFu2.default.uint32('parentTimestamp'), _structFu2.default.uint32('reserved1'), _structFu2.default.char16be('parentUnicodeName', 512), _structFu2.default.struct('parentLocatorEntry', [_structFu2.default.uint32('platformCode'), _structFu2.default.uint32('platformDataSpace'), _structFu2.default.uint32('platformDataLength'), _structFu2.default.uint32('reserved'), _structFu2.default.struct('platformDataOffset', [// Absolute byte offset of the locator data.
_structFu2.default.uint32('high'), _structFu2.default.uint32('low')])], VHD_PARENT_LOCATOR_ENTRIES), _structFu2.default.char('reserved2', 256)]);
// ===================================================================
// Helpers
// ===================================================================
var SIZE_OF_32_BITS = Math.pow(2, 32);
var uint32ToUint64 = function uint32ToUint64(fu) {
return fu.high * SIZE_OF_32_BITS + fu.low;
};
// Returns a 32 bits integer corresponding to a Vhd version.
var getVhdVersion = function getVhdVersion(major, minor) {
return major << 16 | minor & 0x0000FFFF;
};
// Sectors conversions.
var sectorsRoundUp = function sectorsRoundUp(bytes) {
return Math.floor((bytes + VHD_SECTOR_SIZE - 1) / VHD_SECTOR_SIZE);
};
var sectorsRoundUpNoZero = function sectorsRoundUpNoZero(bytes) {
return sectorsRoundUp(bytes) || 1;
};
var sectorsToBytes = function sectorsToBytes(sectors) {
return sectors * VHD_SECTOR_SIZE;
};
// Check/Set a bit on a vhd map.
var mapTestBit = function mapTestBit(map, bit) {
return (map[bit >> 3] << (bit & 7) & BIT_MASK) !== 0;
};
var mapSetBit = function mapSetBit(map, bit) {
map[bit >> 3] |= BIT_MASK >> (bit & 7);
};
var packField = function packField(field, value, buf) {
var offset = field.offset;
field.pack(value, buf, (typeof offset === 'undefined' ? 'undefined' : (0, _typeof3.default)(offset)) !== 'object' ? { bytes: offset, bits: 0 } : offset);
};
var unpackField = function unpackField(field, buf) {
var offset = field.offset;
return field.unpack(buf, (typeof offset === 'undefined' ? 'undefined' : (0, _typeof3.default)(offset)) !== 'object' ? { bytes: offset, bits: 0 } : offset);
};
// ===================================================================
// Returns the checksum of a raw struct.
// The raw struct (footer or header) is altered with the new sum.
function checksumStruct(rawStruct, checksumField) {
var sum = 0;
// Reset current sum.
packField(checksumField, 0, rawStruct);
for (var i = 0; i < VHD_FOOTER_SIZE; i++) {
sum = sum + rawStruct[i] & 0xFFFFFFFF;
}
sum = 0xFFFFFFFF - sum;
// Write new sum.
packField(checksumField, sum, rawStruct);
return sum;
}
function getParentLocatorSize(parentLocatorEntry) {
var platformDataSpace = parentLocatorEntry.platformDataSpace;
if (platformDataSpace < VHD_SECTOR_SIZE) {
return sectorsToBytes(platformDataSpace);
}
return platformDataSpace % VHD_SECTOR_SIZE === 0 ? platformDataSpace : 0;
}
// ===================================================================
var Vhd = function () {
function Vhd(handler, path) {
(0, _classCallCheck3.default)(this, Vhd);
this._handler = handler;
this._path = path;
}
// =================================================================
// Read functions.
// =================================================================
// Returns the first address after metadata. (In bytes)
(0, _createClass3.default)(Vhd, [{
key: 'getEndOfHeaders',
value: function getEndOfHeaders() {
var header = this.header;
var end = uint32ToUint64(this.footer.dataOffset) + VHD_HEADER_SIZE;
var blockAllocationTableSize = sectorsToBytes(sectorsRoundUpNoZero(header.maxTableEntries * VHD_ENTRY_SIZE));
// Max(end, block allocation table end)
end = Math.max(end, uint32ToUint64(header.tableOffset) + blockAllocationTableSize);
for (var i = 0; i < VHD_PARENT_LOCATOR_ENTRIES; i++) {
var entry = header.parentLocatorEntry[i];
if (entry.platformCode !== VHD_PLATFORM_CODE_NONE) {
var dataOffset = uint32ToUint64(entry.platformDataOffset);
// Max(end, locator end)
end = Math.max(end, dataOffset + getParentLocatorSize(entry));
}
}
debug('End of headers: ' + end + '.');
return end;
}
// Returns the first sector after data.
}, {
key: 'getEndOfData',
value: function getEndOfData() {
var end = Math.floor(this.getEndOfHeaders() / VHD_SECTOR_SIZE);
var maxTableEntries = this.header.maxTableEntries;
for (var i = 0; i < maxTableEntries; i++) {
var blockAddr = this.readAllocationTableEntry(i);
if (blockAddr !== BLOCK_UNUSED) {
// Compute next block address.
blockAddr += this.sectorsPerBlock + this.sectorsOfBitmap;
end = Math.max(end, blockAddr);
}
}
debug('End of data: ' + end + '.');
return sectorsToBytes(end);
}
// Returns the start position of the vhd footer.
// The real footer, not the copy at the beginning of the vhd file.
}, {
key: 'getFooterStart',
value: function () {
var _ref = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee() {
var stats;
return _regenerator2.default.wrap(function _callee$(_context) {
while (1) {
switch (_context.prev = _context.next) {
case 0:
_context.next = 2;
return this._handler.getSize(this._path);
case 2:
stats = _context.sent;
return _context.abrupt('return', stats.size - VHD_FOOTER_SIZE);
case 4:
case 'end':
return _context.stop();
}
}
}, _callee, this);
}));
function getFooterStart() {
return _ref.apply(this, arguments);
}
return getFooterStart;
}()
// Get the beginning (footer + header) of a vhd file.
}, {
key: 'readHeaderAndFooter',
value: function () {
var _ref2 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee2() {
var buf, sum, sumToTest, header, sectorsPerBlock, sectorsOfBitmap;
return _regenerator2.default.wrap(function _callee2$(_context2) {
while (1) {
switch (_context2.prev = _context2.next) {
case 0:
_context2.next = 2;
return this._handler.createReadStream(this._path, {
start: 0,
end: VHD_FOOTER_SIZE + VHD_HEADER_SIZE - 1
});
case 2:
_context2.t0 = _context2.sent;
_context2.next = 5;
return streamToBuffer(_context2.t0);
case 5:
buf = _context2.sent;
sum = unpackField(fuFooter.fields.checksum, buf);
sumToTest = checksumStruct(buf, fuFooter.fields.checksum);
// Checksum child & parent.
if (!(sumToTest !== sum)) {
_context2.next = 10;
break;
}
throw new Error('Bad checksum in vhd. Expected: ' + sum + '. Given: ' + sumToTest + '. (data=' + buf.toString('hex') + ')');
case 10:
header = this.header = fuHeader.unpack(buf.slice(VHD_FOOTER_SIZE));
this.footer = fuFooter.unpack(buf);
// Compute the number of sectors in one block.
// Default: One block contains 4096 sectors of 512 bytes.
sectorsPerBlock = this.sectorsPerBlock = Math.floor(header.blockSize / VHD_SECTOR_SIZE);
// Compute bitmap size in sectors.
// Default: 1.
sectorsOfBitmap = this.sectorsOfBitmap = sectorsRoundUpNoZero(sectorsPerBlock >> 3);
// Full block size => data block size + bitmap size.
this.fullBlockSize = sectorsToBytes(sectorsPerBlock + sectorsOfBitmap);
// In bytes.
// Default: 512.
this.bitmapSize = sectorsToBytes(sectorsOfBitmap);
case 16:
case 'end':
return _context2.stop();
}
}
}, _callee2, this);
}));
function readHeaderAndFooter() {
return _ref2.apply(this, arguments);
}
return readHeaderAndFooter;
}()
// Check if a vhd object has a block allocation table.
}, {
key: 'hasBlockAllocationTableMap',
value: function hasBlockAllocationTableMap() {
return this.footer.fileFormatVersion > getVhdVersion(1, 0);
}
// Returns a buffer that contains the block allocation table of a vhd file.
}, {
key: 'readBlockTable',
value: function () {
var _ref3 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee3() {
var header, offset, size;
return _regenerator2.default.wrap(function _callee3$(_context3) {
while (1) {
switch (_context3.prev = _context3.next) {
case 0:
header = this.header;
offset = uint32ToUint64(header.tableOffset);
size = sectorsToBytes(sectorsRoundUpNoZero(header.maxTableEntries * VHD_ENTRY_SIZE));
_context3.next = 5;
return this._handler.createReadStream(this._path, {
start: offset,
end: offset + size - 1
});
case 5:
_context3.t0 = _context3.sent;
_context3.next = 8;
return streamToBuffer(_context3.t0);
case 8:
this.blockTable = _context3.sent;
case 9:
case 'end':
return _context3.stop();
}
}
}, _callee3, this);
}));
function readBlockTable() {
return _ref3.apply(this, arguments);
}
return readBlockTable;
}()
// Returns the address block at the entry location of one table.
}, {
key: 'readAllocationTableEntry',
value: function readAllocationTableEntry(entry) {
return this.blockTable.readUInt32BE(entry * VHD_ENTRY_SIZE);
}
// Returns the data content of a block. (Not the bitmap !)
}, {
key: 'readBlockData',
value: function () {
var _ref4 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee4(blockAddr) {
var blockSize, handler, path, blockDataAddr, footerStart, isPadded, size, buf;
return _regenerator2.default.wrap(function _callee4$(_context4) {
while (1) {
switch (_context4.prev = _context4.next) {
case 0:
blockSize = this.header.blockSize;
handler = this._handler;
path = this._path;
blockDataAddr = sectorsToBytes(blockAddr + this.sectorsOfBitmap);
_context4.next = 6;
return this.getFooterStart();
case 6:
footerStart = _context4.sent;
isPadded = footerStart < blockDataAddr + blockSize;
// Size ot the current block in the vhd file.
size = isPadded ? footerStart - blockDataAddr : sectorsToBytes(this.sectorsPerBlock);
debug('Read block data at: ' + blockDataAddr + '. (size=' + size + ')');
_context4.next = 12;
return handler.createReadStream(path, {
start: blockDataAddr,
end: blockDataAddr + size - 1
});
case 12:
_context4.t0 = _context4.sent;
_context4.next = 15;
return streamToBuffer(_context4.t0);
case 15:
buf = _context4.sent;
if (!isPadded) {
_context4.next = 18;
break;
}
return _context4.abrupt('return', Buffer.concat([buf, new Buffer(blockSize - size).fill(0)]));
case 18:
return _context4.abrupt('return', buf);
case 19:
case 'end':
return _context4.stop();
}
}
}, _callee4, this);
}));
function readBlockData(_x) {
return _ref4.apply(this, arguments);
}
return readBlockData;
}()
// Returns a buffer that contains the bitmap of a block.
//
// TODO: merge with readBlockData().
}, {
key: 'readBlockBitmap',
value: function () {
var _ref5 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee5(blockAddr) {
var bitmapSize, offset;
return _regenerator2.default.wrap(function _callee5$(_context5) {
while (1) {
switch (_context5.prev = _context5.next) {
case 0:
bitmapSize = this.bitmapSize;
offset = sectorsToBytes(blockAddr);
debug('Read bitmap at: ' + offset + '. (size=' + bitmapSize + ')');
_context5.next = 5;
return this._handler.createReadStream(this._path, {
start: offset,
end: offset + bitmapSize - 1
});
case 5:
_context5.t0 = _context5.sent;
return _context5.abrupt('return', streamToBuffer(_context5.t0));
case 7:
case 'end':
return _context5.stop();
}
}
}, _callee5, this);
}));
function readBlockBitmap(_x2) {
return _ref5.apply(this, arguments);
}
return readBlockBitmap;
}()
// =================================================================
// Write functions.
// =================================================================
// Write a buffer at a given position in a vhd file.
}, {
key: '_write',
value: function () {
var _ref6 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee6(buffer, offset) {
return _regenerator2.default.wrap(function _callee6$(_context6) {
while (1) {
switch (_context6.prev = _context6.next) {
case 0:
return _context6.abrupt('return', this._handler.createOutputStream(this._path, {
start: offset,
flags: 'r+'
}).then(function (stream) {
return new _promise2.default(function (resolve, reject) {
stream.on('error', reject);
stream.write(buffer, function () {
stream.end();
resolve();
});
});
}));
case 1:
case 'end':
return _context6.stop();
}
}
}, _callee6, this);
}));
function _write(_x3, _x4) {
return _ref6.apply(this, arguments);
}
return _write;
}()
// Write an entry in the allocation table.
}, {
key: 'writeAllocationTableEntry',
value: function writeAllocationTableEntry(entry, value) {
this.blockTable.writeUInt32BE(value, entry * VHD_ENTRY_SIZE);
}
// Make a new empty block at vhd end.
// Update block allocation table in context and in file.
}, {
key: 'createBlock',
value: function () {
var _ref7 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee7(blockId) {
var offset, blockAddr, blockTable, fullBlockSize, tableOffset, entry;
return _regenerator2.default.wrap(function _callee7$(_context7) {
while (1) {
switch (_context7.prev = _context7.next) {
case 0:
// End of file !
offset = this.getEndOfData();
// Padded on bound sector.
if (offset % VHD_SECTOR_SIZE) {
offset += VHD_SECTOR_SIZE - offset % VHD_SECTOR_SIZE;
}
blockAddr = Math.floor(offset / VHD_SECTOR_SIZE);
blockTable = this.blockTable;
fullBlockSize = this.fullBlockSize;
debug('Create block at ' + blockAddr + '. (size=' + fullBlockSize + ', offset=' + offset + ')');
// New entry in block allocation table.
this.writeAllocationTableEntry(blockId, blockAddr);
tableOffset = uint32ToUint64(this.header.tableOffset);
entry = blockId * VHD_ENTRY_SIZE;
// Write an empty block and addr in vhd file.
_context7.next = 11;
return this._write(new Buffer(fullBlockSize).fill(0), offset);
case 11:
_context7.next = 13;
return this._write(blockTable.slice(entry, entry + VHD_ENTRY_SIZE), tableOffset + entry);
case 13:
return _context7.abrupt('return', blockAddr);
case 14:
case 'end':
return _context7.stop();
}
}
}, _callee7, this);
}));
function createBlock(_x5) {
return _ref7.apply(this, arguments);
}
return createBlock;
}()
// Write a bitmap at a block address.
}, {
key: 'writeBlockBitmap',
value: function () {
var _ref8 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee8(blockAddr, bitmap) {
var bitmapSize, offset;
return _regenerator2.default.wrap(function _callee8$(_context8) {
while (1) {
switch (_context8.prev = _context8.next) {
case 0:
bitmapSize = this.bitmapSize;
if (!(bitmap.length !== bitmapSize)) {
_context8.next = 3;
break;
}
throw new Error('Bitmap length is not correct ! ' + bitmap.length);
case 3:
offset = sectorsToBytes(blockAddr);
debug('Write bitmap at: ' + offset + '. (size=' + bitmapSize + ', data=' + bitmap.toString('hex') + ')');
_context8.next = 7;
return this._write(bitmap, sectorsToBytes(blockAddr));
case 7:
case 'end':
return _context8.stop();
}
}
}, _callee8, this);
}));
function writeBlockBitmap(_x6, _x7) {
return _ref8.apply(this, arguments);
}
return writeBlockBitmap;
}()
}, {
key: 'writeBlockSectors',
value: function () {
var _ref9 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee9(block, beginSectorId, n) {
var blockAddr, endSectorId, offset, bitmap, i;
return _regenerator2.default.wrap(function _callee9$(_context9) {
while (1) {
switch (_context9.prev = _context9.next) {
case 0:
blockAddr = this.readAllocationTableEntry(block.id);
if (!(blockAddr === BLOCK_UNUSED)) {
_context9.next = 5;
break;
}
_context9.next = 4;
return this.createBlock(block.id);
case 4:
blockAddr = _context9.sent;
case 5:
endSectorId = beginSectorId + n;
offset = blockAddr + this.sectorsOfBitmap + beginSectorId;
debug('Write block data at: ' + offset + '. (counter=' + n + ', blockId=' + block.id + ', blockSector=' + beginSectorId + ')');
_context9.next = 10;
return this._write(block.data.slice(sectorsToBytes(beginSectorId), sectorsToBytes(endSectorId)), sectorsToBytes(offset));
case 10:
_context9.next = 12;
return this.readBlockBitmap(this.bitmapSize, blockAddr);
case 12:
bitmap = _context9.sent;
for (i = beginSectorId; i < endSectorId; ++i) {
mapSetBit(bitmap, i);
}
_context9.next = 16;
return this.writeBlockBitmap(blockAddr, bitmap);
case 16:
case 'end':
return _context9.stop();
}
}
}, _callee9, this);
}));
function writeBlockSectors(_x8, _x9, _x10) {
return _ref9.apply(this, arguments);
}
return writeBlockSectors;
}()
// Merge block id (of vhd child) into vhd parent.
}, {
key: 'coalesceBlock',
value: function () {
var _ref10 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee10(child, blockAddr, blockId) {
var blockData, blockBitmap, sectorsPerBlock, i, sectors;
return _regenerator2.default.wrap(function _callee10$(_context10) {
while (1) {
switch (_context10.prev = _context10.next) {
case 0:
_context10.next = 2;
return child.readBlockData(blockAddr);
case 2:
blockData = _context10.sent;
_context10.next = 5;
return child.readBlockBitmap(blockAddr);
case 5:
blockBitmap = _context10.sent;
debug('Coalesce block ' + blockId + ' at ' + blockAddr + '.');
// For each sector of block data...
sectorsPerBlock = child.sectorsPerBlock;
i = 0;
case 9:
if (!(i < sectorsPerBlock)) {
_context10.next = 26;
break;
}
if (mapTestBit(blockBitmap, i)) {
_context10.next = 12;
break;
}
return _context10.abrupt('continue', 23);
case 12:
sectors = 0;
// Count changed sectors.
case 13:
if (!(sectors + i < sectorsPerBlock)) {
_context10.next = 19;
break;
}
if (mapTestBit(blockBitmap, sectors + i)) {
_context10.next = 16;
break;
}
return _context10.abrupt('break', 19);
case 16:
sectors++;
_context10.next = 13;
break;
case 19:
// Write n sectors into parent.
debug('Coalesce block: write. (offset=' + i + ', sectors=' + sectors + ')');
_context10.next = 22;
return this.writeBlockSectors({ id: blockId, data: blockData }, i, sectors);
case 22:
i += sectors;
case 23:
i++;
_context10.next = 9;
break;
case 26:
case 'end':
return _context10.stop();
}
}
}, _callee10, this);
}));
function coalesceBlock(_x11, _x12, _x13) {
return _ref10.apply(this, arguments);
}
return coalesceBlock;
}()
// Write a context footer. (At the end and beginning of a vhd file.)
}, {
key: 'writeFooter',
value: function () {
var _ref11 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee11() {
var footer, offset, rawFooter;
return _regenerator2.default.wrap(function _callee11$(_context11) {
while (1) {
switch (_context11.prev = _context11.next) {
case 0:
footer = this.footer;
offset = this.getEndOfData();
rawFooter = fuFooter.pack(footer);
footer.checksum = checksumStruct(rawFooter, fuFooter.fields.checksum);
debug('Write footer at: ' + offset + ' (checksum=' + footer.checksum + '). (data=' + rawFooter.toString('hex') + ')');
_context11.next = 7;
return this._write(rawFooter, 0);
case 7:
_context11.next = 9;
return this._write(rawFooter, offset);
case 9:
case 'end':
return _context11.stop();
}
}
}, _callee11, this);
}));
function writeFooter() {
return _ref11.apply(this, arguments);
}
return writeFooter;
}()
}, {
key: 'writeHeader',
value: function () {
var _ref12 = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee12() {
var header, rawHeader, offset;
return _regenerator2.default.wrap(function _callee12$(_context12) {
while (1) {
switch (_context12.prev = _context12.next) {
case 0:
header = this.header;
rawHeader = fuHeader.pack(header);
header.checksum = checksumStruct(rawHeader, fuHeader.fields.checksum);
offset = VHD_FOOTER_SIZE;
debug('Write header at: ' + offset + ' (checksum=' + header.checksum + '). (data=' + rawHeader.toString('hex') + ')');
_context12.next = 7;
return this._write(rawHeader, offset);
case 7:
case 'end':
return _context12.stop();
}
}
}, _callee12, this);
}));
function writeHeader() {
return _ref12.apply(this, arguments);
}
return writeHeader;
}()
}]);
return Vhd;
}();
//# sourceMappingURL=vhd.js.map